Endoscopes have attained great acceptance within the medical community, since they provide a means for performing procedures with minimal patient trauma, while enabling the physician to view the internal anatomy of the patient. Over the years, numerous endoscopes have been developed and categorized according to specific applications, such as cystoscopy, colonoscopy, laparoscopy, upper gastrointestinal endoscopy and others. Endoscopes may be inserted into the body's natural orifices or through an incision in the skin. Endoscopes may be rigid or flexible and typically have optical and illuminating features that allow a physician to view the work site. Often during such procedures, it becomes necessary for the physician to evacuate blood clots, mucus, waste or other materials in a body cavity to clear the field of view.
Endoscopes provide limited access to medical tools through a single working channel. To allow for extended access of medical tools, multiple working channels would be advantageous. One such endoscope has been described in U.S. patent application Ser. No. 13/413,252, entitled “Multi Camera Endoscope Assembly Having Multiple Working Channels”, filed on Mar. 6, 2012 by the present Applicant, wherein the endoscope assembly comprises “at least one front-pointing camera and at least one front illuminator associated therewith, at least one side-pointing camera and at least one of side illuminator associated therewith, a first front working channel configured for insertion of a medical tool and a second front working channel configured for insertion of a medical tool.”
Endoscopes typically have valves located at a control unit, also referred to as an endoscope handle for the physician to control a suction line and an air/water line. Conventionally, a physician would use the suction line to clear blood clots, mucus, wastes, among other things. However, with prior art suction line and/or the associated valve, when solid substances or substances with high viscosity (such as coagulated blood, tissue pieces, mucus, wastes and the like) are to be suctioned from inside the body, there are problems that a large load is applied and a passage inside the valve might be clogged by the suctioned substances.
Accordingly, there is a need for a suction control unit that can manage high suction load when substances with high viscosity, large size, or large amount of fluid, such as coagulated blood, tissue pieces, mucus, and wastes, in the lumen are suctioned. There is a need for a suction control unit that can take advantage of two working channels to manage high suction load when needed, and switch to allowing suction through only one of the two working channels when the suction load is low. Thus there is need for the suction control unit to selectively allow for suction to be applied through one or both of the two working channels while a surgical/treatment tool may or may not be inserted through one or both of the two working channels.